Manufacture of aluminium-acetate compounds.



UNITED STATES PATENT OFFICE.

GEORG EICHELBAUM, OF BERLIN, GERMANY, ASSIGNOB TO THE FIRM OF KALLE AND COMPANY, AKTIENGESELLSCHAFT', OF BIEBRICH-ON-THE-RHINE, GERMANY.

MANUFACTURE OF ALUMINIUM- ACETATE COMPOUNDS.

No Drawing.

To all whom it may concern Be it known that I, Gnone EICHELBAUM, doctor of philosophy and chemist, a subject of the King of Prussia, and residing at Augsburgerstrasse 8, Berlin, W. 50, Germany, have invented certain new and useful Improvements in the Manufacture of Aluminium-Acetate Compounds, of which the following is a specification.

When solutions of aluminium acetate are heated or concentrated, insoluble basic salts of aluminium are precipitated. Attempts have been made (see German Patents 9790 and 10488) to avoid this precipitation by the addition of certain acids. The residue obtained after evaporation of such solutions to dryness is however no longer an acetate of aluminium as the acetic acid is displaced by the acid added and evaporated, because of its easy volatility, an aluminium salt of the acid added (tartaric acid, lactic acid, etc.,) being left which no, longer possesses the special therapeutic action of the original acetate, and only small traces of the acetic acid remaining.

This invention relates to a process, by means of which it is possible to obtain compounds which, without the acetate of aluminium being substantially affected, can be evaporated to dryness and yet remain soluble. This is elfected by combining the acetic acid contained in the solution of acetate of aluminium, whether it be combined with the aluminium or in free state, with hexamethylene-tetramin. In this way a double salt, namely hexamethylene-tetramin-aluminiumacetate is obtained. The acetic acid is so to say protected. At the same time there is utilized the. well known property of certain hvdroxyl compounds, such as mannite, glycerin, or oxy-acids, such as citric acid, tartaric acid or their salts, of maintaining in solution compounds of aluminium (as well as of iron). It is advisable in practice not to use the said oxy compounds in a free state, but combined or mixed with an equivalent quantity of hexamethylene-tetramin. Hexamethylene-tetramin is a monoacidic base, the moleefilar weight of which is 140. Equivalent quantities of hexamethylenetetramin and citric acid for instance are therefore 140 parts of the former to 210/3270 parts of the latter (citric acid being a tribasic acid). Owing to the above specification of Letters Patent.

Patented Mar. 23, 1915.

Application filed June 25, 1913. Serial N 0. 775,769.

named formation of the compound hexamethylene tetramin-aluminium-aoetate and the further combination of this product with for instance heXamethylene-tetraminlactate, compounds are produced, which, owing to the fact that they dissociate very readily, combine in an advantageous manner the ellicacious action both-of acetate of aluminum and of the heXamethylene-tetramin which is also antiseptic. At the same time the flavor is improved and rendered less sharp, which is of importance for internal administration of the products.

The process is carried out by causing aluminium acetate, one of the aforementioned compounds which increase the solubility of aluminium acetate, and hexamethylene-tetramin, to react on each other either simultaneously or consecutively. The hexamethylenetetramin is employed in such a quantity as to neutralize completely the acetic acid contained in the aluminium acetate titrable with sodium-hydroxid (NaOH), as well as the second acid added. By titrating aluminium acetate with sodiumhydroxid until phenolphthalein, added as an indicator becomes red, the free acetic acid as well as about one molecule of the acetic acid combined in the al'iminium acetate is neutralized, as is well known. The quantity of hexamethylene-tetramin used according to the present process should be sullicient to combine with the acetic acid determined in this way, as well as with the second acid added, the hexamethylene-tetramin being calculated as a mono-acidic base, as above indicated. The solution thus obtained is then. evaporated to dryness. preferably in a vacuum.

Example 1: 1 kg. of ollicinal aluminium acetate solution (containing 0.085 gr. acetic acid in l cbc. cm.) is mixed at the ordinary temperature with gr. citric acid and 300310 gr. hexa-methylene-tetramin and left standing for some time. The solution thus obtained is then evaporated to dryness in a vacuum at about 60-70". The salt obtained in this manner, is a white crystalline mass of sweet taste, which can be easily reduced to powder. The well known harsh, tart taste of soluble aluminium compounds is no longer perceptible. The preparation is easily soluble in water. The solution does not coagulate when boiled, and does not precipitate any. alumina. The salt is almost insoluble in ether. \Varm dilute alcohol dissolves it almost completely, while it does not completely dissolve in absolute alcohol. It is-alsolargely soluble in benzol. The salt dissolves completely in warm diluted hydrochloric acid (5%) also in acetic acid or glacial acetic acid, and also in diluted sulfuric acid but in the latter case a slight opalescence is noticeable, (due to calcium acetate of the acetate of alumina). Dilute soda lye also dissolves it, and also in this case only a little lime is left as a sediment at the bottom. Acetone dissolves it only partially.

Example2: 1 kg. aluminium acetate (compare Example 1) is mixed with 50 gr. tar- I taric acid and about 285 gr. hexa-methylenetetramin, and then treated in the same way as in the foregoing example. In this way solid white transparent crystals are obtained, the properties of which are the same as those of the salts obtained in the Example 1.

Example 3: 1 kg. aluminium acetate (see Example 1) is mixed with 50 gr. lactic acid and about 265 gr. heXa-methylene-tetramin and treated as stated in Example 1. This gives a white mass of very thick pasty consistency which can be readily pressed in tubes. The properties correspondotherwise to those of the product described in the Example 1.

In place of the solid heXamethylene-tetramin, formaldehyde and ammonia can be used, these reagents combining to form heXamethylene-tetramin iu solution, as is well known. Accordingly the dry hexamethylene-tetramin and the formaldehydeammonia solutions which form hexamethylene-tetramin are equivalents for purposes of the present invention. The use of such formaldehyde-ammonia solutions is illustrated by the following example.

Example 4: 1 kg. of solution of ofiicinal aluminium acetate (compare Example 1) is mixed with 50 gr. citric acid, and the liquid evaporated after adding a mixture of formalin and ammonia in quantities calculated for 300 gr. of hexa-methylene-tetramin. This mixture of formalin and ammonia must be left standing 24 hours before use, until, after a slight heating, the ammonia smell has disappeared. The properties of the end product obtained in that manner, correspond to those described in Example 1.

I claim 1. Theprocess of producing water soluble compounds of aluminium acetate which comprises treating the latter with hexameth' lene-tetramin.

2. he process of producing water soluble compounds of aluminium acetate which comprises treating aluminium acetate solutions with hexamethylenetetramin and evaporating to dryness.

3. The process of producing water soluble compounds of aluminium acetate which comprises treating the same with hexa methylene-tetramin in the presence of compounds increasing the solubility of aluminium compounds.

4. The process of producing water soluble compounds of aluminium acetate which comprises treating aluminium acetate solutions with hexamethylenetetramin and evaporating to dryness in the presence of compounds increasing the solubility of aluminium compounds.

5. The process of producing water soluble compounds of aluminium acetate which comprises treating solutions of aluminium acetate with a solution of hexamethylenetetramin, and evaporating to dryness.

6. The process of producing water soluble compounds of aluminium acetate which comprises treating solutions of aluminium acetate with a solution of hexam'ethylenetetramin, and evaporating. to dryness in the presence of compounds increasing the solubility of aluminium compounds.

7. The process of producing water soluble compounds of aluminium acetate which comprises treatingsolutions of aluminium acetate with a solution of hexamethylene-tetramin, and evaporating to dryness in a vaczuum and at a temperature of about 60 to 0.

8. The process of producing water soluble compounds of aluminium acetate which comprises treating solutions of aluminium acetate with a solution of hexamethylenetetramin, and evaporating to dryness 1n the presence of hydroxyl compounds increasing the solubility of aluminium compounds.

9. A new product comprising a water soluble compound of aluminium acetate and hexamethylene-tetramin.

10. A new product comprising a water soluble compound of aluminium acetate and heXamethylene-tetr'amin combined with a compound increasing the aluminium compounds.

11. A new product comprising a water soluble compound of aluminium acetate and heXamethylene-tetramin combined with a hydroxyl compound increasing the solu-- bility of aluminium compounds.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORG EICHELBAUM.

Witnesses:

HENRY HAsPER, -WoLmsauln HAUPT.

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